Known water- and oil-repellent antifouling finishing agents include those containing a urethane compound having long-chain fluoroalkyl group (e.g. Japanese Unexamined Patent Publications Nos.112855/1978; 74000/1979; and 133485/1979).
However, these antifouling finishing agents have the drawback of poor durability because the long-chain fluoroalkyl group-containing urethane compound (hereinafter referred to as "R.sub.f urethane compound") is low in molecular weight.
To improve the durability, R.sub.f urethane compounds having a molecular weight of 800 to 3000 have been proposed (e.g. Japanese Unexamined Patent Publication No.189284/1983).
Yet the antifouling agents containing the proposed R.sub.f urethane compound have disadvantages. Said R.sub.f urethane compounds are difficult to synthesize and the synthesized compounds are mixtures of various structures. Further said R.sub.f urethane compounds have such low fluorine content that the resulting antifouling finishing agents are not fully satisfactory in any of water and oil repellency and antifouling property.